Pancakes and filaments in cosmological gravitational clustering

We consider the geometrical properties of a distribution of matter evolving under gravitational clustering. Such a distribution can be studied using s tandard statistical indicators such as the correlation function as well as geometrical descriptors sensitive to 'connectedness' such as percolation an alysis and Minkowski functionals. Applying these methods to N-body simulati ons and galaxy catalogues we find that the filling factor at the percolatio n threshold is usually very small reflecting the fact that the Universe con sists of a network of filaments and pancakes, the latter being statisticall y more prominent.